CURRENT ISSUE

Parks

The hottest July in Britain in seven years has just come to a rapid and thundery close. On the way into work, I crossed St James's Park and T-shirts and flip-flops have given way to kagouls and £5 Union Jack umbrellas. Weeks ago, a yellow-green algae had carpeted the lake and the park manager had put up a sign to reassure visitors.

The weed is not harmful, the waterfowl find nutrients in it, and it is an indication of water clarity.